Back pressure valves and two way check valves are used to temporarily seal and contain oil and gas well fluids. For example, a back pressure valve can be used during removal of a pressure control system (e.g. blow out preventer (BOP)) and subsequent installation of production equipment (e.g. production tree). Conventional back pressure valves include various types of spring and plunger designs mounted to openings of tubing and casing hangers that accomplish sealing. However, conventional back pressure valves are not able to be tested once installed, and periodically thereafter if desired at test pressures and operational temperatures. In addition, there are two designs (back pressure valve and two way check valve) that are required for typical operation. This requires the removal of a back pressure valve, installation of a two way check valve to test against, subsequent removal of the two way check valve, and sometimes the subsequent re-installation of the back pressure valve. Therefore, there is a need in the industry for a back pressure valve that can also function as a two way check valve without removal, thus allowing for testing in situ.